With current emphasis on fuel economy, the present trend in motor vehicle body styling is toward a low body silhouette. To maintain adequate interior headroom with the present low roof levels, it is necessary to provide a lower positioning of the vehicle seats. Attendant with the low seat placement, steering columns are now supported in a substantially horizontal position with the steering wheel overlying the driver seat. Low placement of the seat, coupled with the overlying position of the steering wheel, has produced a vehicle that is oftentimes difficult for the driver to enter and leave.
To facilitate ingress and egress of the driver to and from the vehicle, it has been proposed to support the driving wheel and column for swinging movement towards and away from the driver seat.
An adjustable steering wheel is also very desirable to accommodate vehicle operators of different physical size. Accordingly, vehicles are often provided with steering wheel assemblies which are selectively tiltable. In most instances this requires that the steering assembly include a means for holding the steering wheel at a selected position. Many such means have variously tended to be excessively complex, costly, prone to jamming and malfunction or have required undesirably complicated or physically awkward hand movements for the purpose of releasing and engaging a latching mechanism. In many cases, these prior mechanisms restrict access to adjacent portions of the vehicle. Another problem with such means is that installation on preexisting fixed steering wheel assemblies may require extensive modifications, if it is practical at all. Also many such prior mechanisms do not provide a positive locking action, but instead rely on a clamping or wedging action resulting from tightening of threaded elements or the like wherein the resistance of the steering assembly to unwanted tilting is dependent on the force applied to the clamping mechanism.
Such complex designs also tend to result in cumulative manufacturing tolerances creating a looseness in the assembly. Such devices also necessitate the use of a plurality of parts to guide the movement of the many movable members to secure them in selected positions. This proliferation of parts adversely affects the simplicity, cost and reliability of such devices.
U.S. Pat. No. 3,803,939 to Schenten discloses an adjustable tilting steering column, including a pair of brackets, one of which is connected to an instrument panel and the other one of which is connected to the column and which is slidable within the first bracket. A spring-biased clamping cam causes the outer bracket to clamp the inner bracket in any one of an infinite number of positions throughout the range of movement of the movable bracket.
U.S. Pat. No. 3,807,252 to Parr discloses a bracket which holds a steering wheel assembly at a selected position in a positive manner while providing for a convenient release for adjustment to another position. The bracket is secured to the housing for pivotal motion therewith and has a plurality of notches in one edge thereof. A spring-biased push rod has an angled inner end which engages a certain one of the notches on the bracket to hold the steering assembly in a selected position.
U.S. Pat. No. 3,718,053 to Cinadr discloses a tilt steering wheel mechanism including a positioning member and a sliding bolt which cooperate to permit the column to be pivoted to predetermined points about a horizontal axis for locking the wheel in an adjusted position.
U.S. Pat. No. 4,018,101 to Mihalic discloses a positioning device including a control lever operable to disable a pair of latching elements to allow movement and further operative to supply a transverse locking force to a pair of support plates when the movable member is in any selected position.
U.S. Pat. No. 4,335,625 to Nishikawa discloses a tiltable steering shaft mechanism comprising a stationary steering bracket and a swingable steering bracket mounted on the stationary steering bracket for swinging movement about a transversely extending first horizontal axis. A lower steering shaft is carried by the stationary steering bracket and an upper steering shaft is carried by the swingable steering bracket. An adjusting rod is carried by a support bracket which rod threadedly engages an adjusting bracket, which is linearly movable with respect to the support bracket.
Other U.S. patents to which this invention relates include United States patents to Young, Jr. U.S. Pat. No. 3,078,946; Glover et al U.S. Pat. No. 3,267,766; Reed U.S. Pat. No. 3,385,128; Scheffler, Jr. U.S. Pat. No. 3,555,924; Baker U.S. Pat. No. 3,799,569; Krom U.S. Pat. No. 3,851,543 and Broucksou U.S. Pat. No. 4,195,535.